Wireless metropolitan area networks (MAN) are networks implemented over an air interface for fixed, portable, and mobile broadband access systems. Some wireless MANs utilize orthogonal frequency division multiplexing (OFDM) for signaling between mobile terminals and base stations. OFDM is a form of multiplexing that distributes data over a number of carriers that have a very precise spacing in the frequency domain. The precise spacing of the carriers provides several benefits such a high spectral efficiency, resiliency to radio frequency interference and lower multi-path distortion. Due to its beneficial properties and superior performance in multi-path fading wireless channels, OFDM has been identified as a useful technique in the area of high data-rate wireless communication, for example wireless metropolitan area networks (MAN). Orthogonal frequency division multiple access (OFDMA) is a multiple access technology that utilizes OFDM techniques.
MIMO antenna systems are also being considered for incorporation into wireless MANs. MIMO systems use multiple transmitting and multiple receiving antennas for communication of information. MIMO antenna systems allow spatial diversity. Spatial diversity that takes advantage of transmitting data from multiple sources that have a known physical spacing.
Currently there are methodologies for dealing with particular aspects of wireless MAN, for example OFDM communications. However, these methodologies do not deal with ways to incorporate the newer concepts of MIMO. In addition, both MIMO and non-MIMO wireless MANs are continuing to introduce and support additional functionality that requires numerous additional types of feedback information to be transmitted from the wireless terminal to the base station. In some cases the feedback mechanisms of the current methodologies cannot support the transmission of the additional number of types of feedback information. Furthermore, the current methodologies are limited in the capacity of information that they can feedback from the wireless terminal to the base station.